This is an energy related invention and it is recognized that there have been schemes provided in the past for attempting to derive useful heat by use of a motor, a pump and a hydraulic medium which is treated in a way to increase the heat thereof. One example of this is the provision of a pair of tubs, one slightly spaced within the other, with oil between the two. A means is provided to rotate one of the tubs relative to the other tending to heat the oil and provide heat simply through the use of electric power, for the general purpose of saving fossil fuel. These schemes have not turned out to be practical, or efficient. As the oil heats, it thins and becomes less viscous so that the heating action of the rotating tub is lessened. It is the general purpose of the present invention to provide a new and improved hydraulic heat generator which is not only useful but is efficient in operation, the efficiency being generally maintained.